1. Field of the Invention
The present invention relates to compositions and method useful in the removal of road film and dirt from vehicles such as cars, trucks, motorcycles, snowmobiles, bicycles, vans, buses, trailers, railway trains and the like. These compositions and methods may be used manually, with hand operated cleaning equipment or in automatic cleaning equipment without the assistance of mechanical action. The methods of the invention may be practiced with a) low pressure, no contact cleaning methods, b) high pressure scrubbing application of the compositions, c) friction wash with low or high pressure fluid application, d) presoak cleaning in ‘touchless’ and friction-type vehical washes, e) clean-in-place (closed environment) washing systems, especially for aluminum, or any variation of cleaning formats known within the art.
2. Background of the Invention
It is desirable to keep the exposed surfaces of vehicles clean for reasons which include at least maintaining the appearance of the vehicle, minimizing surface tarnishing of the vehicle, reducing paint wear and fading, and preventing corrosion on the vehicle. Each of these adverse affects on vehicles are at least in part contributed to by materials which collect on the vehicle during use and storage. It is well known that regular surface care and washing of the vehicle can assist in maintaining the appearance of the vehicle and can even extend its useful life where corrosion damage is concerned. It is therefore desirable to have products available to the market place which can assist in the cleaning and washing of vehicle surfaces.
Unfortunately, the roadways are not uniform in the materials which contribute to the deposits left on vehicles. The composition of materials transferred from the roadways to cars (often along with moisture from the surface of the roadway) even changes with the seasons. The more obvious changes in the compositions of the road surface contaminants transferred to vehicles occur during the Winter, when anti-icing materials (e.g., salt, pumice, organic solvents such as ethylene glycol from anti-freeze solutions, sand) are regularly applied to the roadways. The salt used on roadways may often contain mineral oils or vegetable oils as an additive. Less obvious roadway contaminants may appear where agricultural materials used on fields in the Spring and Summer may run onto the road surfaces. Incompletely burned hydrocarbons, leaking vehicle fluids, and spills also contribute to the mix of road dirt which can be transferred onto vehicles. This vast variation in possible materials which may accumulate on cars is also complicated by the fact that soil compositions vary from region to region.
It is commercially undesirable to have to provide a vast array of cleaning solutions or concentrates from which cleaning solutions must be prepared which have to be chosen on the basis of the type of road-film which is thought to be present on a vehicle. The use or need for a wide range of different cleaning solutions would require increased work in designing, packaging and formulating specific cleaning compositions, and would require the user to select the appropriate cleaning solution for each particular vehicle to be cleaned. This would be a very undesirable situation. It is therefore important to attempt to provide cleaning solutions with the widest range of capability with respect to the removal of the most common types of road-film and dirt from vehicles. This is not any easy task because, as noted above, the components of the road-film might comprise organic materials, inorganic materials, hydrophilic materials, hydrophobic materials, acidic materials, or basic materials. It has therefore been a difficult task in designing cleansing compositions for the removal of road-film from vehicles which have a broad range of applicability for the different types of film which may be deposited on the vehicles.
Some mechanical action and/or aggressive fluid application pressure may be necessary in some application to remove traffic film. This can also complicate the compounding of the solutions as certain ingredients useful at lower pressure applications may cause foaming when used with stronger mechanical forces or higher pressure applications. If too high a fluid application pressure is used, the pressure can damage the surface without removing the traffic film. Prior cleaners remove some dirt but the traffic film was not completely removed. Additionally, attempts at providing cleaning solutions which are compatible with the cleaning of such significantly different soil compositions has encountered a problem wherein the ingredients of the proposed cleaning solutions are incompatible, either reacting with one another or separating during storage. The use of hydrofluoric acid solutions, although effective in cleaning certain clear metal surfaces, may be avoided where possible in commercial operations and requires careful control in industrial settings because of the corrosive strength of the HF.
U.S. Pat. No. 4,093,566 describes a phosphate-free spray cleaner for metals utilizing sodium metasilicates, sodium carbonate and EDTA dissolved in water with an ethoxylated wetting agent.
U.S. Pat. No. 4,153,571 describes a heat dependent alkali gel cleaning composition based on alkali metal hydroxides and various nonionic surfactants. Also, U.S. Pat. No. 4,099,985 describes the combination of sodium metasilicate, alkali metal hydroxide and non-ionic surfactants in an aqueous system for cleaning metal surfaces.
U.S. Pat. No. 4,284,435 describes a cleaning composition and method for removing road film from transportation vehicles without the necessity of mechanical brushing or wiping of the surface using high pressure spray equipment. The composition comprises 2 to 30% by weight of chelating agent; 1 to 12% by weight of a bis(ethoxylated) quaternary ammonium compound; 0.5% to 5% by weight ethoxylated alcohol nonionic surfactant; 0-5% by weight sodium metasilicate and water. This concentrate is diluted with water and applied to the surface at a pressure of above 400 psi. Among the chelating agents described are ethylenediamine tetraacetic acid (EDTA) and its salts and hydroxyethylenediamine triacetic acid (HEDTA) and its salts.
U.S. Pat. Nos. 3,123,640 and 3,141,905 describe cation-active surface active chemical compounds, the latter patent specifically describing their use for bactericidal, germicidal, antiseptic, algaecidal, fungicidal, textile softening, corrosion inhibition, antistatic, emulsifying, foam modifying, ore beneficiation, and various other purposes. The cation-active compounds are quaternary ammonium compounds derived from lower monoalkyl dialkanolamines. The cation-active compounds include a) dialiphatic, dialkoxylated quaternary ammonium compounds, and b) monoaliphatic, trialkoxylated quaternary ammonium compounds, as described by formulae in the patents.
One other significant problem with the design of washing solutions is the fact that where the cleaning product to be used in a wash is attempting to remove materials with different properties (e.g., water-soluble and oleophilic materials), the ingredients for the wash solution are likely to be incompatible. Therefore instability in the stored washing compositions and in the diluted wash solutions is highly likely. This instability may take the form of reactivity between ingredients and physical incompatibility between compounds which leads to separation of components or phases. These incompatibility effects can lead directly to reduced performance in the washing process and variability in the performance of the washing process.